This invention relates to a two-part fastening device or clip made from a hard-elastic plastic material for fastening protective strips or decorative moldings to bearer plates or trim panels, such as, for example, the body panels of a motor vehicle.
A known fastening device of this type is shown, for example, in German Patent 31 14 283 A1. This device includes an upper part, which is connectable to the protective strip, and lower part having a downwardly opening socket, which can be inserted into a hole in the panel and fixed to the edge of the hole by means of elastically yielding locking elements. The lower part is elastically sealed with respect to the panel by a sealing diaphragm. The upper part includes a cover plate that is insertable into the protective strip, and a stopper that extends out perpendicularly from the cover plate for insertion into the socket of the lower part. The stopper has a bulge on its free end that tapers conically in both axial directions, and the socket of the lower part has an opening, constricted in relation to the stopper, through which the bulge of the stopper extends and locks behind to hold the upper part in the lower part.
This known type of fastening device is usually first inserted into the protective strip in a pre-assembled state, and then the protective strip is fastened to the bodywork panel by pressing the socket of the lower part into a hole in the panel until the locking elements engage behind the edge of the hole.
The fastening principle behind this type of device makes it relatively easy to use, but it has the critical disadvantage that water can easily penetrate between the strip and the bodywork and from there it is able to penetrate unhindered through the opening in the socket, which is open at both ends and get behind the panel to which the strip is affixed. This sooner or later is bound to lead to corrosion at various locations of the non-protected panel. In view of the current demand of motor vehicle owners to eliminate corrosion problems, this type of clip is no longer generally acceptable.
An object of the present invention therefore is to provide a fastening device of the type described that prevents water from penetrating into the fastening holes in the body panel.